Independent signalling method for bearer management

ABSTRACT

Independent signalling method for bearer management in a communication network with transporting bearer resource request message of both the UE and RN via Base station to managing entity of RN within EPC, as a signalling message over uplink channel referred to as ‘Union of Resource Request (UR Request)’ message. The bearer resource response message referred to as ‘Independent Admission Response (IA Response)’ from one of the management entity of EPE or management entities of UE and RN within EPC are transported as a signalling message to Evolved Packet Edge (EPE) via Base station over the downlink channel. This manages bearer setup signalling as a single loop, by transportation of ‘UR Request’ signalling message and receiving one “Independent Admission Response” signalling message over uplink and downlink channels respectively. EPE is a conglomeration of network nodes comprising of UEs, RNs and all other network nodes that communicate over EPC via Base station.

FIELD OF THE INVENTION

The present disclosure relates to bearer management in a wirelesscommunication network. In particular, the invention relates to transportof signalling messages on the interface between a relay node and anothernode in a mobile communication network.

BACKGROUND

In order to provide better qualities of service and wider communicationranges between wireless nodes, the concept of relay station has beenintroduced in network systems. The purpose of deploying relay station orRelay Node (RN) in network system is to extend the serving coverage ofbase station; hence, user equipment (UE) which is not within thecommunication coverage of base station can access the services providedby relay node as well via base station.

Wireless network architecture as defined by 3GPP introduces wirelessrelay node (RN) entity to extend the coverage of base station (evolvedNode B or eNodeB or eNB). A long term evolution-advanced (LTE-A) system,as its name implies, is an evolution of the LTE system, consideringrelaying for cost-effective throughput enhancement and coverageextension. For example, a relay can be deployed at the cell edge wherethe eNB is unable to provide required radio quality/throughput for theUEs or at certain location where radio signals of the eNB cannot cover.

The Relay Node (RN) forms an independent physical cell. From a userequipment (UE) perspective, the RN is seen as a usual base station. TheRN is connected via a wireless link to the base station. The relay nodearchitecture deployment foresees that a RN emulates a base station forthe UE, which means that the UE would see the RN as a usual basestation. From the network side, the RN is seen as a usual UE by the basestation. The base station or eNB to which the RN is connected, is calledDonor-eNB (DeNB) hereinafter referred to as Base station or eNB andoperates as a usual base station. The deployment of RN in the 3GPPnetwork architecture is described in 3GPP Technical Specification36.806; “Relay architectures for E-UTRA (LTE-Advanced)”.

In order for the user equipment to receive a service from the network,it needs to establish connectivity via base station, by initiatingNon-Access Stratum (NAS) signalling messages with network nodes likeMobility Management Entity (MME) serving the UE. Consequentialsignalling messages are exchanged between network nodes to allocatebearer resources for UE and RN to service the UE request. The abovebearer management procedure can be initiated by UE or the Evolved PacketCore (EPC in terms of 3GPP LTE) or simply the communication network.Similar procedures are followed for managing existing bearers. Themanaging functions include creating new entry, updating and deleting.

Thus, whenever a UE bearer is created or modified, the RN bearer modifyor create procedures may be initiated by the RN. This increases theexchange of messages separately for the UE and for the RN tomodify/create a new bearer. Thus additional messages may be exchanged bythe RN each time a bearer is created/modified for the UE, leading todelayed access service and as well as backhaul bandwidth is wasted orunderutilized. Therefore, there is a need for a bearer management tooptimize radio and backhaul resources by effectively setting-up thebearers.

SUMMARY OF THE INVENTION

The summary represents the simplified condensed version of the claimedsubject matter and it is not an extensive disclosure of the claimedsubject matter. The summary neither identifies key or critical elementsnor delineates the scope of the claimed subject matter. The summarypresents the simplified form of the claimed subject matter and acts as aprelude to the detailed description that is given below.

The present invention and its embodiments are made to provide for afeasible solution for facilitating bearer management in a communicationnetwork optimizing exchange of signalling communication in managingbearers for UE and RN.

An aspect of the invention provides for a method of managing bearersignalling in a communication network, by transporting “Union ofResource Request” (UR Request) signalling message from Evolved PacketEdge (EPE) entities to managing entities of RN via Base station andreceiving “Independent Admission Response” (IA Response) signallingmessage for the transported UR Request from the management entity of EPEby Base station, wherein the said management entity serves/manages allthe entities in the EPE. EPE is a conglomeration of network nodescomprising of user equipment, relay nodes and all other network nodesthat communicate with EPC via Base station. Network nodes in the EPE mayestablish connectivity external to EPC like Internet or PSTN (PublicSwitch Telephone Network).

Another aspect relates to receiving “Independent Admission Response” (IAResponse) signalling message for the transported UR Request frommanagement entities of EPE by the Base station, wherein at least one ofthe said management entities are not serving/managing the same entitiesin the EPE.

Another aspect relates to network nodes like RN, Base station, MME_RNand MME_UE and systems facilitating the above method of managing bearerseach comprising of at least a receiver, for receiving the said messages,processors for executing the functions, transmitter for transmittingmessages, a memory for storing information and retaining instructionsfor executing functions associated with the above methods.

Other aspects, advantages, and salient features of the invention willbecome apparent to those skilled in the art from the following detaileddescription, which, taken in conjunction with the annexed drawings,discloses exemplary embodiments of the invention.

DESCRIPTION OF THE DRAWINGS

The features, advantages and other aspects of the embodiments of thepresent invention will be obvious to any person skilled in the art toappreciate the invention when read with the following description takenin conjunction with the accompanying drawings.

FIG. 1 is an illustration of existing bearer establishment procedure foruser equipments (UE) and relay node (RN) as specified in 3GPP LTE (A)network architectures.

FIG. 2 shows the network nodes conglomeration between two networkentities in accordance with the principles of the invention.

FIG. 3 represents ‘UR Request’ message signalling in the uplink fromEvolved Packet Edge to Evolved Packet Core via Base station inaccordance with the embodiments of the invention.

FIG. 4 shows a detailed method of tagging (UE_TAG) in any one of thecontrol plane protocol layers in accordance with the embodiments of theinvention.

FIG. 5 represents bearer establishment signalling loop in accordancewith various aspects of the invention.

The figures are not drawn to scale and are illustrated for simplicityand clarity to help understand the various embodiments of the presentinvention. Throughout the drawings it should be noted that likereference numbers are used to depict the same or similar elements,features and structures.

DETAILED DESCRIPTION

The following descriptions with reference to the accompanying drawingsare provided to assist in a comprehensive understanding of exemplaryembodiments of the invention as defined by the claims and theirequivalents. Accordingly, those of ordinary skill in the art willrecognize that various changes and modifications of the embodimentsdescribed herein can be made without departing from the scope and spiritof the invention.

The terms and words used in the following description and claims are notlimited to the bibliographical meanings, but, are merely used by theinventor to enable a clear and consistent understanding of theinvention. The terms, component, module, system, and the like areintended to refer to an entity or entities within a communicationnetwork node comprising of; hardware, software, a combination ofhardware and software. For eg., a component may be, but not limited tobeing, a process running on a processor, a processor, an integratedcircuit, or a computer. Both an application running on a computingdevice and the computing device can be a component. A component may belocalized on one computer and/or distributed between two or morecomputers. The components may communicate by way of local and/or remoteprocesses.

Those skilled in the art will understand that the principles of thepresent disclosure may be implemented in any suitably arranged systems.The terms used to describe various embodiments are exemplary. It shouldbe understood that these are provided to merely aid the understanding ofthe description, and that their use and definitions in no way limit thescope of the invention.

The present invention and its embodiments are mainly described inrelation to 3GPP specifications and standards (LTE-Advanced) forapplicability of certain exemplary embodiments. The terminology used istherefore related thereto. Such terminology is used in the context ofdescribing the embodiments of the invention and it does not limit theinvention in any way. Any other network architecture or systemdeployment, etc., may also be utilized as long as it is compliant withthe features described herein.

In particular, embodiments of the present invention may be applicable inany relay-enhanced (cellular) system with a need for signallingoptimization. Embodiments of the present invention may be applicablefor/in any kind of modern and future communication network including anymobile/wireless communication networks/systems.

Example embodiments to be described below are not intended to limit thepresent invention to any specific example, embodiment, environment,applications, or particular implementations described in these exampleembodiments. It should be appreciated that, in the following exampleembodiments and the attached drawings are illustrated for the ease ofunderstanding, but not to limit the actual scale.

The following paragraphs will describe various embodiments of theinvention. For exemplary purposes only, most of the embodiments areoutlined according to the LTE-Advanced mobile communication system withthe solution to the problem discussed in the background. It should benoted that the invention may be advantageously used in connection withthe communication system described above, but the invention is notlimited to its use in this particular exemplary communication network.The explanations given below are intended to better understand specificexemplary embodiments described herein and should not be understood aslimiting the invention to the specific implementations of processes andfunctions in a mobile communication network. The improvements/solutionsproposed herein may be readily applied in architectures/systems havingrelevance to relay architectures. Some embodiments of the invention mayalso make use of standard and improved procedures of thesearchitectures/systems.

The techniques described herein may be used for various wirelesscommunication networks such as CDMA networks, CDMA implementing radiotechnology such as UTRA, TDMA networks, TDMA implementing radiotechnology such as GSM, FDMA networks, OFDMA networks, OFDDAimplementing radio technology such as Evolved UTRA (E-UTRA), SC-FDMAnetworks.

User equipment (UE) used in the following description denotes variousterminologies used like an access terminal (AT), wireless communicationdevice, terminal, wireless handset, computer or wireless module,wireless module for use with a computer, personal digital assistant(PDA), tablet computer or device. In the overall architecture of anetwork with a relay node (RN), a relay node has a base station and aterminal side called as user equipment (UE). Towards UE the RN behavesas a conventional eNB using the access link (Uu interface) and the UE isnot aware of whether it is communicating with a relay node or a basestation. Relay nodes are therefore transparent for the UE. Towards basestations relay nodes initially operate as a UE using the radio interfaceto connect to the base station. Once connection is established and therelay node is configured, the relay uses a subset of the UEfunctionality for communication on the backhaul link (Un interface). Inrelay architecture Base station acts as a proxy between the core networkand the relay node. From the relay perspective, it appears as if RN isdirectly connected to the core network and the Base station appears as amobility management entity (MME) for the S1 interface and a base station(eNB) for X2 interface towards the relay node. From the perspective ofcore network, the relay node appears as it belongs to the Base station.

The UEs are connected to the RN by means of an Uu interface and the RNto the Base station by means of Un interface. When the network e.g., MMEhas no valid location or routing information for the UE, the UE cannotbe reached. This is more likely when the UE is in a state of switchedoff, or out of coverage area. 3GPP defines this state as a de-registeredstate and this could also happen when the UE is in non-3GPP access. Whenthe UE is attached to the network e.g., MME, it can receive Core Networkservices. This state is defined by 3GPP as registered state. In thisregistered state the UE can be in two different connection managementstates like RRC_IDLE state and RRC_CONNECTED state. When no data isbeing transmitted and the radio resources are released, the UE has avalid IP configuration. In such idle state there is no Non-AccessStratum (NAS) signalling connection between the UE and the network,e.g., MME. Also during the idle state there is no S1 connection betweenthe eNB and the Serving Gateway. In the RRC_CONNECTED state, there is anactive connection between the UE and Base station, which implies acommunication context being stored within the Base station for this UE.Both sides can exchange user data and or signalling messages overlogical channels.

From the wireless network perspective, protocol structure for the Userand Control planes correspond to user data transmission and signallingtransmission. Control plane corresponds to the information flowsactually considered as signalling by E-UTRAN and Core Network. Thisincludes all the RRC (Radio Resource Control) E-UTRAN signalling(supporting functions such as Radio Bearer management, radio mobility,user paging) and NAS (Non Access Stratum) signalling. On the radiointerface, the Control plane uses the Control plane protocol stacknamely PDCP (Packet Data Convergence Protocol), RLC (Radio LinkControl), MAC (Medium Access Control) and PHY (Physical) stack totransport both RRC and Core Network NAS signalling. The above protocolstack layers support the same functions for both the User and ControlPlanes. When a Non-Access Stratum (NAS) signalling connection needs tobe established between UE and the MME routed via relay node, the UE andthe MME shall enter the connected state.

It should be noted that Base station is in fact connected to one or morethan one MME or Serving GW node. These pluralities of Base station forma pool area such that a pool area can be served by one or several MMEand/or Serving GW. A given MME or Serving GW node may serve one orseveral pool areas. The connectivity of the relay node and the UEcommunicating via relay node, is managed by the network e.g., MME. Basedon initial NAS signalling, MMEs in the pool analyzes the request anddetermines which MME should manage the radio resources for therespective relay node or the UE communicating via relay node. Thiscommunication message essentially comprising of bearer requestacknowledgement, indicates the uplink channel through which the UE is tocommunicate for establishing radio bearers. For the sake of simplicityMME managing the UE and the MME managing the RN is indicated as MME_UEand MME_RN respectively, hereinafter.

FIG. 1 shows the signalling message for bearer initiation procedureexisting in 3GPP LTE specification. UE 20 sends an initial NAS messageor service request to the MME_UE 101 a, which is routed through RN 10and Base station 30. When a NAS layer in the UE has to send an initialNAS message denoted as ‘UE NAS Msg’ in FIG. 1, the UE first initiatesthe establishment of the Radio Resource Control (RRC) connection overthe Uu interface. The RRC procedures are elaborated in 3GPPspecification TS 36.331 available at www.3gpp.org. In parallel to theestablishment of the RRC connection over the Uu interface, the RNinitiates the establishment of the RRC connection over the Un interface.The RRC connection establishment procedure over the Uu and Un interfacesare identical.

The NAS message is directed to MME (UE) 101 a and the RN 10 istransparent. The MME_UE 101 a understands the message and forwards it tothe SGW/PGW_UE 102 a for checking the UE subscription data. Then theSGW/PGW_UE 102 a in conjunction with PCRF (not shown) authorizes MME_UE101 a to create a dedicated bearer and sends the message over S11interface (Interface between S/PGW and MME). On receiving the response,MME_UE 101 a sends bearer setup request to the UE 20 as an S1-AP messagerouted through RN 10. RN 10 understands this S1-AP message and initiatesRRC configuration between UE 20 and RN 10. A bearer setup response isthen sent by UE 20 to MME_UE 101 a routed via RN 10 and Base station 30as an S1-AP message. On receiving the response from UE 20, MME_UE 101 aestablishes the bearers and sends the response to SGW/PGW_UE 102 a. Thisprocess establishes radio bearers to enable data flow from theSGW/PGW_UE 102 a to the UE 20. After completion of this procedure, theRN 10 may send a NAS message seeking bearer-resource request to MME_RN101 b through Base station 30. MME_RN 101 b understands the message andprovisions bearer resource allocation to RN 10. Upon receiving bearerresource allocation, RN 10 bearer establishment is completed. Radioresources for the relay node 10 are allocated so as to serve the alreadyestablished UE's bearer requirements. The above process of initiatingbearer establishment can also be initiated by EPC/Core Network. Thishappens both when the UE 20 is in the RRC_IDLE state and a message/datais to be transported to the UE 20 by the Core Network or when there is achange in existing bearer configuration to the UE 20 in theRRC_CONNECTED state. In this state, MME_UE 101 a initiates bearer-setupor modify procedure for the UE 20 at any point of time based on UEsubscription and QoS requirements. Thus in all the above instances of UENAS Messages, whenever a UE 20 bearer is created or modified, the RNbearer, modify or create may be initiated subsequently by the RN 10.Thus additional messages are exchanged separately for the UE 20 and forthe RN 10 to modify/create a new bearer. This either wastes orunderutilizes the backhaul bandwidth. Further, there is delay in trafficflow.

FIG. 2 shows the network nodes conglomeration between two networkentities in accordance with the principles of the invention. Networkentity 625 is called as Evolved Packet Edge (EPE) comprising ofplurality of network nodes like UE, RN and all other nodes thatcommunicate with Evolved Packet Core Network entity 675 via Base station30. Network nodes in the EPE 625 may establish connectivity external toEPC like Internet 106 or PSTN (Public Switch Telephone Network) 107. EPCentity 675 comprises of network nodes like Mobility Management Entity(MME), Serving gate way/Packet gate way (S/PGW), Policy of ChargingRules Function etc., These nodes essentially manages the entities in theEPE. For e.g., a UE bearer resource request is processed and allowedonly by the MME serving the UE. Depending on the complexity of thecommunication network, it so happens that, MMEs are segregated toperform management of plurality of UE and RN separately. In such cases,it is appropriate to indicate MMEs serving the UEs as MME_UE and MMEsserving the RNs as MME_RN.

As part of bearer management signalling as envisaged, a communicationfrom EPE 625 comprising of bearer resource request of both the UE and RNis transported via Base station 30 to EPC as a single signalling messageover uplink channel 651 hereinafter referred to as “Union of ResourceRequest” (UR Request) message.

The response message comprising of bearer resource response from eitherone of the managing entity or managing entities of EPC 675 aretransported as a single signalling message to Base station 30 over thedownlink channel 652 hereinafter referred to as “Independent AdmissionResponse” (IA Response). This manages bearer setup signalling loop, witha single transportation of ‘UR Request’ signalling message and receiving“Independent Admission Response” signalling message over uplink anddownlink channels respectively.

FIG. 3 represents “UR Request” message signalling in the uplink from EPEto EPC 675 via Base station 30 in accordance with the embodiments of theinvention. When the UE 20 is in the state of RRC_CONNECTED or RRC_IDLE;a UE NAS signalling message requesting bearer resource of the form‘Create, Update, Detach, Modify’ etc., hereinafter referred to as “CRUD”messages, are generated. It so happens that, depending on the complexityof the EPE communication network, multiple relay nodes may be wirelesslyconnected in a sequence so as to serve a distant UE. In such cases, abearer request of a UE initiated by sending a UE NAS message to the MMEin the EPC 675 has to be routed via all the relay nodes acting insequence. Such an arrangement is shown towards the right of EPE 625.

The UE NAS message generated by UE 20 is received at the first upstreamrelay node (RN). The first relay node encapsulates the said received UENAS message in the RN1 NAS message by adding the identity of UE (UE_ID).The RN1 NAS message thus created by first relay node is received by thesecond upstream relay node, which encapsulates the said received RN1 NASmessage in its RN2 NAS message by adding the identity of the downstreamrelay node (RN1_ID) as this RN is the UE for the upstream relay node.Relay node identity or RN_ID is a unique identifier that uniquelyidentifies the MME serving the said RN. Relay node identity comprises ofMME Group ID, MME code of MME_RN. The encapsulated RN2 NAS message isreferred to as tagged message (UE_TAG) and represented as “UR Request”.Similar tagging is done for any number of such upstream relay nodes. Theabove said tagged message is forwarded to the managing entity of RNwithin EPC 675 via Base station 30. The tagged message is available atthe MME_RN within EPC as “UR Request” message.

In case of a single relay node, encapsulated ‘RN NAS message with UE_ID’forms the tagged message. Depending on the mobility of the UE within EPEof a communication network, it so happens that, a single UE may beconnected to different relay nodes. Such circumstances may arise basedon the mobility of the UE and/or proximity of the UE with a RNexhibiting excellent signal strength. In such cases, a bearer request ofa UE initiated by sending a UE NAS message to the MME in the EPC 675 hasto be routed through the respective RN which is coupled to the UE. Suchan arrangement is shown towards the left of EPE 625.

FIG. 4 depicts protocol layers through which insertion of UE_TAG(comprising of UE_ID and type prefix for the said UE_ID) by the RN 10preferably at NAS layer or any one of the control plane protocol layersof S1-AP, SCTP, PDCP, RLC, MAC, PHY, is accomplished in accordance withthe embodiments of the invention. For the sake of illustration the flowof uplink signalling data in case of two radio bearers is shown withpossible UE_TAG insertion points, at any one of the protocol layers. Forthe sake of brevity, the control plane protocol layer 410 above PDCPlayer 401 is shown as an integrated layer comprising of NAS, S1-AP, andSCTP (Stream Control Transmission Protocol).

The PDCP layer 401 performs IP-header compression and ciphering. A PDCPheader is added, carrying information required for deciphering in theUE. The output from the PDCP is forwarded to the RLC layer 402. The RLCprotocol performs concatenation and/or segmentation of the PDCP ServiceData Units (SDUs) and adds an RLC header. The RLC Service Data Units(PDUs) are forwarded to the MAC layer 403, which multiplexes a number ofRLC SDUs and attaches a MAC header to form a transport block. Finallythe Physical layer 404 attaches a CRC (Cyclic Redundancy Check) to thetransport block for error-detection purposes and transmits the resultingsignal using transmit antennas. In the above protocol structure,possible insertion of UE_TAG 301 (shown by arrow headers) could be atany one of the layers. For e.g., UE_TAG 301 can be preferably insertedat header junction of layer 410, or at PDCP header junction of layer401, or at RLC header junction of layer 402 or at MAC header junction oflayer 403 or at any junction of the PHY layer 404. Similarly for eachradio bearer signalling flow a possible UE_TAG 301 could be inserted atany one of the protocol layers as explained above.

FIG. 5 represents bearer setup signalling loop, with a singletransportation of “UR Request” signalling message by EPE entities andreceiving “Independent Admission Response” signalling message by Basestation over uplink and downlink channels respectively, in accordancewith the embodiments of the present invention. For the sake ofsimplicity, UE coupled with one RN is shown. When the UE 20 is in thestate of RRC_CONNECTED (1) or RRC_IDLE (0), (Step 1) CRUD messages aregenerated by UE or initiated by EPC. In either case, UE 20 generateseither single or multiple bearer resource requests within a single NASmessage thereby triggering the establishment of RRC connection with theRN 10 in case UE is in RRC_IDLE (0) mode. RN 10 also starts theestablishment of the RRC connection with the Base station 30 in case RNis in RRC_IDLE (0) state. Both these RRC procedures over the respectiveUu and Un interface are elaborated in 3GPP specification TS 36.331.

When the RN 10 receives the UE NAS Message (Step 2), relay nodeencapsulates the said received UE NAS message in the RN NAS message byadding the identity of UE (UE_ID) (Step 3) to be sent to the MME_RN 101b via Base station 30. Without loss of generality the denotation ‘UE NASMsg+UE_ID’ will be called as ‘UE_TAG’ which means that it is a taggedmessage essentially consisting of UE NAS Message with UE_ID (Step 4).The above denotation is specifically defined for the purpose of thisinvention as a tagged message denoted as UE_TAG. In the case of multiplerelay nodes upstream (For e.g., RN1 and RN2), the first upstream relaynode RN1 encapsulates the said received UE NAS message in the RN1 NASmessage by adding the identity of UE (UE_ID) at any one of the controlplane protocol layers S1-AP, SCTP, PDCP, RLC, MAC, PHY preferably overNAS. The RN1 NAS message thus created by first relay node is received bythe second upstream relay node RN2, which encapsulates the said receivedRN1 NAS message in its RN2 NAS message by adding the identity of thedownstream relay node (RN1_ID) as this RN is the UE for the upstreamrelay node. The encapsulated RN2 NAS message is referred to as taggedmessage (UE_TAG) and represented as “UR Request”. Similar tagging isdone for any number of such upstream relay nodes

The UE_TAG is then transmitted from the RN 10 to the MME_RN 101 b viaBase station 30 over Un interface as a control plane signalling message.When this UE_TAG arrives at Base station 30, Base station 30 understandsthe message to be a ‘UE_TAG’ message except when tagged at NAS layer,and then forwards it to MME_RN 101 b; the MME_RN 101 b, understands themessage and if the tagged message is not a “UR Request” message ittreats as ‘other control plane signalling message’. If the taggedmessage is a CRUD message then the MME_RN 101 b de-capsulates UE 20 NASmessage and forwards the request to MME_UE 101 a using the identity ofUE. In case of multiple relay nodes, the RN2 NAS message received by theBase station from the downstream relay node is forwarded to the mobilitymanagement entity serving the said downstream relay node (MME_RN2). Thesaid MME_RN2 understands the received RN2 NAS message and de-capsulatesthe message and forwards the RN1 NAS message if found, within the saidreceived RN2 NAS message to the mobility management entity serving thesaid relay node (MME_RN1) based on the identity of relay node. MME_RN1understands the received RN1 NAS message and de-capsulates the ‘UE NASmessage’ if found, and forwards the ‘UE NAS message’ along with theidentity of MME_RN2 and any other MME_RN identities which are in thesequence of receiving the RN NAS message to MME_UE based on the UEidentity inside RN1 NAS message (Step 5). The thumb rule for providingthe identities of MME_RN to next node is that, identities of all MME_RNsvia which the message has traversed except the identity of the nodewhich is forwarding the message shall be provided to the next MME node.

When the UE NAS message is received and understood by the MME_UE 101 ato be a bearer resource request message (Step 6), MME_UE 101 a grantsutmost UE request and generates ‘S1-AP message for UE’ and relay noderesource request (RR request) message for granted resources by MME_UE(Step 7). The above messages are forwarded to Base station 30 and MME_RN101 b respectively. In case of multiple relay nodes in sequence, MME_UE101 a generates relay node resource request (RR request) messages forgranted resources by MME_UE, for MME_RNs identified by MME_RN identitiesand forwards it to the respective MME_RNs. If the MME_UE 101 a findsthat the UE NAS Message does not pertain to UE 20 bearer request, thenthe received message is handled as ‘other control plane signallingmessage’ and if the MME_UE 101 a does not grant UE 20 bearer request atstep 7, then MME_UE 101 a generates ‘UE NAS message for bearer resourcereject’ and forwards it for UE 20 via Base station 30 (Step 14).

The ‘RR Request’ message generated by the MME_UE 101 a for MME_RN 101 bis a bearer request on behalf of RN 10. The message essentially is anestablishment of RN bearer to serve UE bearer QoS requirements. (Fore.g., the ‘RR Request’ message may be that, some bandwidth is guaranteedfor the UE 20 which is being served by the RN 10 (RN_ID). Hence MME_RN101 b is required to process RN 10 bearer request. The ‘RR Request’ isthen forwarded to MME_RN 101 b. MME_RN processes the ‘RR Request’forwarded by MME_UE (Step 8). Once RN 10 bearer request is granted,MME_RN 101 b generates ‘S1-AP message for RN’ (Step 10) and forwards tothe Base station 30 directly. If the MME_RN 101 b does not grant ‘RRRequest’ made by MME_UE 101 a at Step 8, then MME_RN 101 b generates ‘RNNAS message for bearer resource reject’, and then forwards it to Basestation 30 (Step 9). In case of multiple relay nodes, the generated‘S1-AP message for RNs’ comprises of bearer resource allocation messagefor all the relay nodes. Base station 30 processes the received ‘S1-APmessage for RN’ (Step 12) and performs RRC configuration for thedownstream relay node and forwards ‘S1-AP messages’ for the remainingEPE entities. Performing RRC configuration for the downstream relay nodeby Base station at Step 11 and Step 12 and performing RRC configurationby relay node to the subsequent downstream relay nodes or performing RRCconfiguration by the first upstream relay node to the UE (Step 13) aresimilar to those functions elaborated in 3GPP specification

The ‘S1-AP message for UE’ and ‘S1-AP message for RN or RNs at step 7and step 10 are available to Base station 30 as “Independent AdmissionResponse” (IA Response) messages. “Independent Admission Response”comprises of bearer resource allocation message pertaining to therespective EPE entities. For e.g., if MME_UE grants bearer resource (x)to the UE (Y), it generates an ‘S1-AP message for UE’ and forwards toBase station which may be in the form of Y(x) and then generates ‘RRRequest’ message seeking bearer allocation for the relay nodes (P,Q,R)and forwards to the respective MME_RNs. The ‘RR Request’ message may bein the form of Yx(P,Q,R). MME_RNs may grant the same resources (‘x’) tothe respective relay nodes (P, Q, R). In such cases MME_RNs may generate‘S1-AP message for RNs’ which may be in the form of x(P,Q,R) andforwards it to Base station. The “Independent Admission (IA) Response”from MME_UE i.e., Y(x), is understood by the Base station as a messagecomprising of allocated bearer resources corresponding to the value of‘x’ to UE. “Independent Admission Response” from MME_RNs i.e., x(P,Q,R)is understood by the Base station as a message comprising of allocatedbearer resources corresponding to the value of ‘x’ for the relay nodes‘P’, ‘Q’ and ‘R’ respectively. In the above given example, in caseMME_RNs grants bearer resources for each relay node P,Q,R, correspondingto the value less than the granted value of UE i.e., ‘x-a’, then the‘S1-AP message for RNs’ would be in the form ‘(P,Q,R)(b,b,b)’, (wherex−a=b). When this “IA Response” message is received by Base station, itunderstands as a message comprising of allocated bearer resourcescorresponding to the value of ‘b’ for the respective relay nodes ‘P’,‘Q’ and ‘R’. Further, in the above given example, in case MME_RNmanaging the relay node ‘P’ grants bearer resources corresponding to thevalue less than the granted value of UE i.e., ‘x−d’; and MME_RN managingthe relay node ‘Q’ grants bearer resources corresponding to the valueless than the granted value of RN ‘P’ i.e., ‘x−e’; and MME_RN managingthe relay node ‘R’ grants bearer resources corresponding to the valueless than the granted value of RN ‘Q’ i.e., ‘x−f’ wherein (f<e<d), thenthe “IA Response” message that is generated by MME_RNs would be‘(P(d),Q(e),R(f))’. When this “IA Response” is received by the Basestation, it understands it as a message comprising of allocated bearerresources corresponding to the value of ‘d’ for ‘P’, ‘e’ for ‘Q’, and‘f’ for ‘R’. In the given example, in case MME_RN grants bearerresources for the relay node ‘P’ corresponding to the value ‘g’; grantsbearer resources for the relay node ‘Q’ corresponding to the value ‘h’;and denies granting any of the bearer resources for the relay node ‘R’,then the “IA Response” message that is generated by MME_RN would be‘P(g), Q(h), R( )’ comprising of ‘S1-AP messages’ for the granted relaynodes (P and Q) and ‘RN NAS message for bearer resource reject’ to therelay node (R). When this “IA Response” is received by the Base station,it understands as a message comprising of allocated bearer resourcescorresponding to the value of ‘g’ for ‘P’, ‘h’ for ‘Q’ and ‘RN NASmessage for bearer resource reject’ for ‘R’.

Another embodiment of the invention relates to the implementation of theabove described various embodiments using hardware and software. It isrecognized that the various embodiments of the invention may beimplemented or performed using computing devices (processors). Acomputing device or processor may for e.g., be general purposeprocessors, digital signal processors (DSP), application specificintegrated circuits (ASIC), field programmable gate arrays (FPGA) orother programmable logic devices, etc. The various embodiments of theinvention may also be performed or embodied by a combination of thesedevices

Further, the various embodiments of the invention may also beimplemented by means of software modules, which are executed by aprocessor or directly in hardware. Also a combination of softwaremodules and a hardware implementation may be possible. The softwaremodules may be stored on any kind of computer readable storage media,for example RAM, EPROM, EEPROM, flash memory, registers, hard disks,CD-ROM, DVD, etc.

It is to be noted that respective functional blocks or elementsaccording to above-described aspects can be implemented by any knownmeans, either in hardware and/or software, respectively, if it is onlyadapted to perform the described functions of the respective parts. Thementioned method, steps can be realized in individual functional blocksor by individual devices, or one or more of the method, steps can berealized in a single functional block or by a single device.

The present invention also covers any conceivable combination of methodsteps and operations described above, and any conceivable combination ofnodes, apparatuses, modules or elements described above, as long as theabove-described concepts of methodology and structural arrangement areapplicable. It should be further noted that the individual features ofthe different embodiments of the invention may individually or inarbitrary combination be subject matter to another invention.

It would be appreciated by a person skilled in the art that numerousvariations and/or modifications may be made to the present invention asshown in the specific embodiments without departing from the spirit orscope of the invention as broadly described. The present embodimentsare, therefore, to be considered in all respects to be illustrative andnot restrictive.

We claim:
 1. A method for bearer management signalling in acommunication network, the method comprising of; Forming “Union ofResource (UR) Request” message in the Evolved Packet Edge (EPE), whereinEPE includes user equipment (UE) and at least one relay node (RN) andthe like; Transporting the “UR Request” message from the EPE via Basestation to managing entity of relay nodes (RNs) within EPC, wherein‘managing entity of RNs’ are network nodes that manage or administerRNs, like mobility management entity serving the relay node (MME_RN),serving gate way, packet gate way, PCRF, HSS or combination thereof; andReceiving “Independent Admission (IA) Response” by the Base station forthe transported “UR Request” from one of the said management entity,wherein the said management entity is the mobility management entitythat serves/manages all the entities in the EPE.
 2. A method for bearermanagement signalling in a communication network, the method comprisingof; Forming “Union of Resource (UR) Request” message in the EvolvedPacket Edge (EPE), wherein EPE includes user equipment (UE) and at leastone relay node (RN) and the like; Transporting the “UR Request” messagefrom the EPE via Base station to managing entity of relay nodes (RNs)within EPC, wherein ‘managing entity of RNs’ are network nodes thatmanage or administer RNs like mobility management entity serving therelay node (MME_RN), serving gate way, packet gate way, PCRF, HSS orcombination thereof; and Receiving “Independent Admission (IA) Response”by the Base station for the transported UR Request, from the managemententities of EPE within EPC wherein at least one of the said managemententity is the mobility management entity not serving/managing the sameentities in the EPE.
 3. The method of claim 1, wherein forming “URRequest” comprises of; Tagging the NAS message received by the relaynode, wherein tagging includes adding user equipment identity (UE_ID)with the said received NAS message, at least in any one of the controlplane protocol layers like S1-AP, SCTP, PDCP, RLC, MAC, PHY, preferablyover NAS; Constructing an RN NAS message by encapsulating the receivedNAS message along with tag, wherein the NAS message is UE NAS messagewhen coupled to UE, and wherein the NAS message is RN NAS message whencoupled to UE via another relay node; and wherein UE_ID is RN_ID whencoupled to UE via another relay node; Forwarding the said RN NASmessage, now called as ‘tagged message’ to the MME_RNs via Base station.4. The method of claim 2, wherein forming “UR Request” comprises of;Tagging the NAS message received by the relay node, wherein taggingincludes adding user equipment identity (UE_ID) with the said receivedNAS message, at least in any one of the control plane protocol layerslike S1-AP, SCTP, PDCP, RLC, MAC, PHY, preferably over NAS; Constructingan RN NAS message by encapsulating the received NAS message along withtag, wherein the NAS message is UE NAS message when coupled to UE, andwherein the NAS message is RN NAS message when coupled to UE via anotherrelay node; and wherein UE_ID is RN_ID when coupled to UE via anotherrelay node; Forwarding the said RN NAS message, now called as ‘taggedmessage’ to the MME_RNs via Base station.
 5. The method of claim 1further comprising of; Receiving the tagged message by MME_RN; Grantingutmost “UR Request” by the said MME_RN, wherein granting includesstoring relay node identities (RN_IDs), understanding, and generating“IA Response” message if accepted and generating ‘UE NAS message forbearer resource reject’ if rejecting for the said received taggedmessage; and Forwarding to Base station, one among the messagescomprising of: ‘UE NAS message for bearer resource reject’, ‘S1-APmessage for UE’ and ‘S1-AP message for RNs’ for the relay nodesidentified by the said relay node identities (RN_IDs);
 6. The method ofclaim 2 further comprising of; Receiving the tagged message by MME_RNs;Understanding the said received tagged message, ‘un-tagging’ andforwarding ‘RN NAS Message’, forwarding ‘UE NAS Message’, forwardingidentities of MME_RNs to management entities serving the relay nodes andmanagement entity serving the user equipment respectively, wherein‘un-tagging’ includes, identifying ‘RN NAS Message’ UE NAS Message',identifying TAGs (UE_TAG and RN_TAGs) within the said received taggedmessage. Receiving ‘UE NAS Message’ by MME_UE and granting utmost “URRequest” by the said MME_UE, wherein granting includes, understanding,rejecting, accepting, and generating ‘UE NAS message for bearer resourcereject’ if rejecting, generating ‘S1-AP message for UE’ and relay noderesource request (RR request) message for MME_RNs identified by relaynode identities (RN_IDs) for the granted UE resources by MME_UE, ifaccepting, for the said received tagged message; Forwarding to Basestation, one among the generated messages comprising of: ‘S1-AP messagefor UE’, ‘UE NAS message for bearer resource reject’; Forwarding thegenerated ‘RR Request’ message to MME_RNs identified by relay nodeidentities (RN_IDs); Receiving ‘RR Request’ message by MME_RNs fromMME_UE; Granting utmost “RR Request” by the said MME_RNs, whereingranting includes, understanding, rejecting, accepting, and generating‘RN NAS message for bearer resource reject’ if rejecting, generating‘S1-AP message for RNs’ for the relay nodes identified by the said relaynode identities (RN_IDs), if accepting, for the said received “RRRequest” message; and Forwarding to Base station, one among thegenerated messages comprising of: ‘RN NAS message for bearer resourcereject’, ‘S1-AP message for RNs’, for the relay nodes identified by thesaid relay node identities (RN_IDs).
 7. A bearer management signallingsystem for relay node in a communication network comprising of; Areceiver for receiving NAS Message, ‘S1-AP message of UE’ and ‘S1-APmessage for RNs’; A processor for tagging wherein, tagging includesadding user equipment identity (UE_ID) with the said received NASmessage, at least in any one of the control plane protocol layers likeS1-AP, SCTP, PDCP, RLC, MAC, PHY, preferably over NAS; wherein the NASmessage is UE NAS message when coupled to UE, and wherein the NASmessage is RN NAS message when coupled to UE via another relay node; andwherein UE_ID is RN_ID when coupled to UE via another relay node; Aprocessor for constructing an RN NAS message by encapsulating thereceived NAS message along with the said TAG; A transmitter fortransmitting RN NAS message towards the managing entity via Basestation; A processor for understanding the received ‘S1-AP Message fordownstream node’, ‘RN NAS message’ and ‘UE NAS message’ from Basestation and performing RRC configuration, if the received message is an‘S1-AP Message’; A transmitter for transmitting, ‘NAS message’, RRCradio bearer configuration message, ‘S1-AP message’ to EPE entities; andA memory that retains instructions for executing functions associatedwith the receiver, processor/processors, and transmitter and as well asmeasured or computed data that may be generated during executing suchfunctions.